Occupancy with single occasion for one level of factor

[jCeradini]

Hi Analyzers,

In a single-season occupancy model, I have 10 occasions of detections from camera traps (each camera occ = 2 wks) and a single occasion of detections from a scat survey (with species ID based on genetics). So, each site has 11 occasions (10 camera, 1 scat) and n = 64 sites. Scat surveys were just a single survey at the site (scat was collected for DNA lab analysis). No attempts were made to have multiple scat surveys (occasions) per site. Scat search time and other relevant covariate data were collected per site.

Can I estimate p ~ survey method (camera vs. scat)? I have a binary time-varying covariate for survey method for each occasion. Models run fine, and the estimates make sense (way higher for scat than camera...for multiple reasons, like representing animal use over different time periods). But, there's only one scat occasion per site. So, can I estimate p ~ scat? If so, does it change the interpretation of the beta in any way?

These papers demonstrate methods for single-occasion occupancy models, so that gives me some hope:

https://academic.oup.com/jpe/article/5/1/22/1296465
"In general, site occupancy and detection probability parameters can be estimated using a single survey provided (i) probability of occupancy and probability of detection depend on covariates and (ii) the set of covariates that affect occupancy and the set of covariates that affect detection differby at least one variable."

https://besjournals.onlinelibrary.wiley ... 2664.12925

Thanks!